mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 09:19:51 +00:00
![Takashi Iwai](/assets/img/avatar_default.png)
Replace all tasklet_hi_schedule() callers with the normal tasklet_schedule(). The former often causes troubles with RT-kernels, and has actually no merit. Signed-off-by: Takashi Iwai <tiwai@suse.de>
188 lines
4.1 KiB
C
188 lines
4.1 KiB
C
/*
|
|
* RTC based high-frequency timer
|
|
*
|
|
* Copyright (C) 2000 Takashi Iwai
|
|
* based on rtctimer.c by Steve Ratcliffe
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
*
|
|
*/
|
|
|
|
#include <linux/init.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/moduleparam.h>
|
|
#include <linux/log2.h>
|
|
#include <sound/core.h>
|
|
#include <sound/timer.h>
|
|
|
|
#if defined(CONFIG_RTC) || defined(CONFIG_RTC_MODULE)
|
|
|
|
#include <linux/mc146818rtc.h>
|
|
|
|
#define RTC_FREQ 1024 /* default frequency */
|
|
#define NANO_SEC 1000000000L /* 10^9 in sec */
|
|
|
|
/*
|
|
* prototypes
|
|
*/
|
|
static int rtctimer_open(struct snd_timer *t);
|
|
static int rtctimer_close(struct snd_timer *t);
|
|
static int rtctimer_start(struct snd_timer *t);
|
|
static int rtctimer_stop(struct snd_timer *t);
|
|
|
|
|
|
/*
|
|
* The hardware dependent description for this timer.
|
|
*/
|
|
static struct snd_timer_hardware rtc_hw = {
|
|
.flags = SNDRV_TIMER_HW_AUTO |
|
|
SNDRV_TIMER_HW_FIRST |
|
|
SNDRV_TIMER_HW_TASKLET,
|
|
.ticks = 100000000L, /* FIXME: XXX */
|
|
.open = rtctimer_open,
|
|
.close = rtctimer_close,
|
|
.start = rtctimer_start,
|
|
.stop = rtctimer_stop,
|
|
};
|
|
|
|
static int rtctimer_freq = RTC_FREQ; /* frequency */
|
|
static struct snd_timer *rtctimer;
|
|
static struct tasklet_struct rtc_tasklet;
|
|
static rtc_task_t rtc_task;
|
|
|
|
|
|
static int
|
|
rtctimer_open(struct snd_timer *t)
|
|
{
|
|
int err;
|
|
|
|
err = rtc_register(&rtc_task);
|
|
if (err < 0)
|
|
return err;
|
|
t->private_data = &rtc_task;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
rtctimer_close(struct snd_timer *t)
|
|
{
|
|
rtc_task_t *rtc = t->private_data;
|
|
if (rtc) {
|
|
rtc_unregister(rtc);
|
|
tasklet_kill(&rtc_tasklet);
|
|
t->private_data = NULL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
rtctimer_start(struct snd_timer *timer)
|
|
{
|
|
rtc_task_t *rtc = timer->private_data;
|
|
if (snd_BUG_ON(!rtc))
|
|
return -EINVAL;
|
|
rtc_control(rtc, RTC_IRQP_SET, rtctimer_freq);
|
|
rtc_control(rtc, RTC_PIE_ON, 0);
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
rtctimer_stop(struct snd_timer *timer)
|
|
{
|
|
rtc_task_t *rtc = timer->private_data;
|
|
if (snd_BUG_ON(!rtc))
|
|
return -EINVAL;
|
|
rtc_control(rtc, RTC_PIE_OFF, 0);
|
|
return 0;
|
|
}
|
|
|
|
static void rtctimer_tasklet(unsigned long data)
|
|
{
|
|
snd_timer_interrupt((struct snd_timer *)data, 1);
|
|
}
|
|
|
|
/*
|
|
* interrupt
|
|
*/
|
|
static void rtctimer_interrupt(void *private_data)
|
|
{
|
|
tasklet_schedule(private_data);
|
|
}
|
|
|
|
|
|
/*
|
|
* ENTRY functions
|
|
*/
|
|
static int __init rtctimer_init(void)
|
|
{
|
|
int err;
|
|
struct snd_timer *timer;
|
|
|
|
if (rtctimer_freq < 2 || rtctimer_freq > 8192 ||
|
|
!is_power_of_2(rtctimer_freq)) {
|
|
snd_printk(KERN_ERR "rtctimer: invalid frequency %d\n",
|
|
rtctimer_freq);
|
|
return -EINVAL;
|
|
}
|
|
|
|
/* Create a new timer and set up the fields */
|
|
err = snd_timer_global_new("rtc", SNDRV_TIMER_GLOBAL_RTC, &timer);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
timer->module = THIS_MODULE;
|
|
strcpy(timer->name, "RTC timer");
|
|
timer->hw = rtc_hw;
|
|
timer->hw.resolution = NANO_SEC / rtctimer_freq;
|
|
|
|
tasklet_init(&rtc_tasklet, rtctimer_tasklet, (unsigned long)timer);
|
|
|
|
/* set up RTC callback */
|
|
rtc_task.func = rtctimer_interrupt;
|
|
rtc_task.private_data = &rtc_tasklet;
|
|
|
|
err = snd_timer_global_register(timer);
|
|
if (err < 0) {
|
|
snd_timer_global_free(timer);
|
|
return err;
|
|
}
|
|
rtctimer = timer; /* remember this */
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void __exit rtctimer_exit(void)
|
|
{
|
|
if (rtctimer) {
|
|
snd_timer_global_free(rtctimer);
|
|
rtctimer = NULL;
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* exported stuff
|
|
*/
|
|
module_init(rtctimer_init)
|
|
module_exit(rtctimer_exit)
|
|
|
|
module_param(rtctimer_freq, int, 0444);
|
|
MODULE_PARM_DESC(rtctimer_freq, "timer frequency in Hz");
|
|
|
|
MODULE_LICENSE("GPL");
|
|
|
|
MODULE_ALIAS("snd-timer-" __stringify(SNDRV_TIMER_GLOBAL_RTC));
|
|
|
|
#endif /* CONFIG_RTC || CONFIG_RTC_MODULE */
|